Opportunistic passive multistatic radar processing for automotive radar

This application claims priority to European Patent Application No. 23169362.3, filed on Apr. 24, 2023, and entitled “OPPORTUNISTIC PASSIVE MULTISTATIC RADAR PROCESSING FOR AUTOMOTIVE RADAR”. The entirety of this application is incorporated herein by reference.

An autonomous vehicle perceives objects surrounding the autonomous vehicle based upon the sensor signals generated by sensor systems of the autonomous vehicle to enable navigating a driving environment. For example, the autonomous vehicle may include various sensor systems, such as a radar system, a camera system and/or a lidar system, for generating sensor signals. The autonomous vehicle also includes a centralized processing device that receives data based upon the sensor signals generated by the sensor systems and performs a variety of different tasks, such as detection of vehicles, pedestrians, and other objects. Based on an output of the processing device, the autonomous vehicle may perform a driving maneuver.

As the number of autonomous vehicles that operate in a driving environment increase, instances of cross-radar interference likewise increase. Moreover, some autonomous vehicles include a plurality of radar systems, which also leads to increased instances of cross-radar interference. When autonomous vehicles are within proximity of each other (e.g., within radar range), radar systems of the autonomous vehicles can interfere with each other. Within a fleet of autonomous vehicles, cross-radar interference can be more problematic since radar systems of the autonomous vehicles in the fleet are oftentimes time synchronized. For instance, the radar systems of the autonomous vehicles in a fleet can be offset at specific millisecond triggers from integer seconds from vehicle clocks. Further, the vehicle clocks can be closely synchronized with global positioning system (GPS) signals. As a result, the radar systems from multiple autonomous vehicles in the fleet can operate during common time periods, which increases the likelihood of overlapping signals entering acquisition windows of at least some of the radar systems.

According to an illustration, radar systems of two autonomous vehicles operating within proximity can interfere with each other due to timing synchronization between the radar systems. Following this illustration, the radar systems of the autonomous vehicles can each include a transmitter and a receiver. A first transmitter of the first radar system of the first autonomous vehicle and a second transmitter of the second radar system of the second autonomous vehicle can both transmit radar signals into a driving environment during substantially similar time periods. Accordingly, a first receiver of the first radar system can receive, from the driving environment, a reflected radar signal responsive to the radar signal transmitted by the first transmitter of the first radar system as well as an interfering radar signal responsive to the radar signal transmitted by the second transmitter of the second radar system. Similarly, a second receiver of the second radar system can receive, from the driving environment, a reflected radar signal responsive to the radar signal transmitted by the second transmitter of the second radar system as well as an interfering radar signal responsive to the radar signal transmitted by the first transmitter of the first radar system. Thus, in such a scenario, cross-radar interference can be experienced by the first radar system and the second radar system of the autonomous vehicles, which detrimentally impacts operation of the radar systems as well as the autonomous vehicles that include the radar systems.

The following is a brief summary of subject matter that is described in greater detail herein. This summary is not intended to be limiting as to the scope of the claims.

Described herein are various technologies in which automotive radar systems opportunistically employ passive multistatic radar processing. An autonomous vehicle includes a radar system, which includes a transmitter and a receiver. The radar system can be controlled to operate in an active mode during a first time period as the autonomous vehicle travels along a route through the driving environment. Both the transmitter and the receiver of the radar system are enabled when operating in the active mode. Moreover, the radar system can be controlled to operate in a passive mode during a second time period as the autonomous vehicle travels along the route through the driving environment. The transmitter of the radar system is disabled and the receiver of the radar system is enabled when operating in the passive mode. While operating in the passive mode, the receiver of the radar system can receive a reflected radar signal from the driving environment; the reflected radar signal can be responsive to a radar signal transmitted by a differing radar system of a differing autonomous vehicle operating within proximity of the radar system of the autonomous vehicle. Further, an object in the driving environment can be detected based on the reflected radar signal and transmission information pertaining to the differing radar system of the differing autonomous vehicle.

In various embodiments, a server computing system can control whether the radar system of the autonomous vehicle is to operate in the active mode or the passive mode. The server computing system can similarly control whether other radar systems of other autonomous vehicles are to operate in the active mode or the passive mode. In other embodiments, the autonomous vehicles can control whether the respective radar systems are to operate in the active mode or the passive mode. Pursuant to an illustration, the autonomous vehicles can perform a negotiation therebetween to set the modes for the respective radar systems.

According to various embodiments, a server computing system can identify that a first radar system of a first autonomous vehicle and a second radar system of a second autonomous vehicle are likely to experience cross-radar interference during a time period as the first autonomous vehicle travels along a first route through a driving environment and the second autonomous vehicle travels along a second route through the driving environment. The first autonomous vehicle and the second autonomous vehicle are in a fleet of autonomous vehicles. Moreover, the server computing system can select the first radar system of the first autonomous vehicle to operate in the active mode and the second radar system of the second autonomous vehicle to operate in the passive mode during the time period. A first transmitter and a first receiver of the first radar system of the first autonomous vehicle are both enabled when operating in the active mode. A second transmitter of the second radar system of the second autonomous vehicle is disabled and a second receiver of the second radar system of the second autonomous vehicle is enabled when operating in the passive mode. Moreover, the server computing system can transmit, to the second autonomous vehicle, a control signal to cause the second radar system to operate in the passive mode during the time period. The second autonomous vehicle can receive the control signal and the second radar system can operate in the passive mode during the time period responsive to the control signal. Further, the server computing system can transmit, to the first autonomous vehicle, a control signal to cause the first radar system to operate in active mode during the time period. The first autonomous vehicle can receive the control signal and the first radar system can operate in the active mode during the time period responsive to the control signal.

The server computing system can also transmit transmission information pertaining to the radar systems to the autonomous vehicles. Following the example set forth above where the server computing system selects the first radar system of the first autonomous vehicle to operate in the active mode and the second radar system of the second autonomous vehicle to operate in the passive mode during the time period, the server computing system can further transmit, to the second autonomous vehicle, transmission information pertaining to the first radar system of the first autonomous vehicle. The transmission information pertaining to the first radar system can include location information specifying a location of the first radar system, waveform information specifying a waveform of a radar signal transmitted by the first transmitter of the first radar system, and/or timing information specifying timing of the radar signal transmitted by the first transmitter of the first radar system. The transmission information pertaining to first radar system can be utilized by the second radar system to detect an object in the driving environment (from a reflected radar signal received by the second receiver of the second radar system).

According to other embodiments, an autonomous vehicle having a radar system can control whether the radar system is to operate in the active mode or the passive mode. The autonomous vehicle can identify that the radar system and a differing radar system of a differing autonomous vehicle are likely to experience cross-radar interference. The autonomous vehicle can select the radar system of the autonomous vehicle to operate in the active mode and the differing radar system of the differing autonomous vehicle to operate in the passive mode during a first time period. The autonomous vehicle can send transmission information pertaining to the radar system to the differing autonomous vehicle during the first time period. Moreover, the autonomous vehicle can select the radar system of the autonomous vehicle to operate in the passive mode and the differing radar system of the differing autonomous vehicle to operate in the active mode during the second time period. Pursuant to an illustration, the foregoing selections can be made as part of a negotiation between the autonomous vehicle and the differing autonomous vehicle. Moreover, the autonomous vehicle can receive transmission information pertaining to the differing radar system of the differing autonomous vehicle (e.g., the transmission information can be received from the differing autonomous vehicle, from a server computing system, etc.); such transmission information can be utilized by the autonomous vehicle to detect object(s) when operating in the passive mode.

The above summary presents a simplified summary in order to provide a basic understanding of some aspects of the systems and/or methods discussed herein. This summary is not an extensive overview of the systems and/or methods discussed herein. It is not intended to identify key/critical elements or to delineate the scope of such systems and/or methods. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

Various technologies pertaining to opportunistically employing passive multistatic radar processing in automotive radar systems are now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate describing one or more aspects. Further, it is to be understood that functionality that is described as being carried out by certain system components may be performed by multiple components. Similarly, for instance, a component may be configured to perform functionality that is described as being carried out by multiple components.

Moreover, the term “or” is intended to mean an inclusive “or” rather than an exclusive “or.” That is, unless specified otherwise, or clear from the context, the phrase “X employs A or B” is intended to mean any of the natural inclusive permutations. That is, the phrase “X employs A or B” is satisfied by any of the following instances: X employs A; X employs B; or X employs both A and B. In addition, the articles “a” and “an” as used in this application and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from the context to be directed to a singular form.

As used herein, the terms “component” and “system” are intended to encompass computer-readable data storage that is configured with computer-executable instructions that cause certain functionality to be performed when executed by a processor. The computer-executable instructions may include a routine, a function, or the like. It is also to be understood that a component or system may be localized on a single device or distributed across several devices. Further, as used herein, the term “exemplary” is intended to mean “serving as an illustration or example of something.”

As used herein, the terms “first”, “second”, etc. are used for identification purposes; these terms are not intended to convey an ordering unless otherwise specified or clear from the context.

As described herein, one aspect of the present technology is the gathering and use of data available from various sources to improve quality and experience. The present disclosure contemplates that in some instances, this gathered data may include personal information. The present disclosure contemplates that the entities involved with such personal information respect and value privacy policies and practices.

Examples set forth herein pertain to an autonomous vehicle including a radar system that opportunistically operates in active mode or passive mode to mitigate cross-radar interference between the radar system and differing radar system(s) of differing autonomous vehicle(s). It is to be understood, however, that the radar system described herein can be employed in a variety of different scenarios, such as flight, in drone technologies, in augmented reality (AR) or virtual reality (VR) technologies, in non-autonomous vehicles (e.g., in a fleet of non-autonomous vehicles), and so forth. Autonomous vehicles are set forth herein as one possible use case, and features of the claims are not to be limited to autonomous vehicles unless such claims explicitly recite an autonomous vehicle.

Referring now to the drawings,illustrates an exemplary driving environmentthat includes an autonomous vehicleand an autonomous vehicle(collectively referred to herein as autonomous vehicles-) that opportunistically employ passive multistatic radar processing. While two autonomous vehicles-are depicted in the driving environmentof, it is to be appreciated that the examples set forth herein can be extended to the driving environmentincluding substantially any number of autonomous vehicles (e.g., more than the two autonomous vehicle-). The autonomous vehicleincludes a radar system, and the autonomous vehicleincludes a radar system.

The autonomous vehicleincludes componentry depicted in callout. Thus, the autonomous vehicleincludes the radar system, a mechanical system(e.g., a vehicle propulsion system, a braking system, a steering system, etc.), and a computing systemhaving a radar control systemincorporated therein. The radar control systemis configured to control the radar systemto operate in an active mode or a passive mode during a given time period. The radar control systemis further configured to change the mode in which the radar systemoperates over time as described in greater detail herein (e.g., the radar control systemcan cause the radar systemto switch from operating in an active mode during a first time period to operating in a passive mode during a second time period, and vice versa). Further, it is contemplated that the autonomous vehicle(as well as other autonomous vehicles that can be in the driving environment) can be substantially similar to the autonomous vehicledescribed herein.

While the autonomous vehicleis shown as including one radar system, it is contemplated that the autonomous vehiclecan include a plurality of radar systems similar to the radar system. The plurality of radar systems can be located around the autonomous vehicleand can have different fields of view relative to the autonomous vehiclecovering differing portions of the driving environmentsurrounding the autonomous vehicle. Each of the radar systems of the autonomous vehiclecan be independently controlled by the radar control system. The autonomous vehiclecan likewise include a plurality of radar systems similar to the radar system.

As described in greater detail herein, cross-radar interference between the radar systemof the autonomous vehicleand the radar systemof the autonomous vehiclecan be mitigated by opportunistically controlling the modes of the radar systems-(e.g., active mode versus passive mode) as the autonomous vehicles-travel through the driving environmentalong respective routes. Further, the techniques employed herein can enable enhancing radar perception utilizing the radar systems-of the autonomous vehicles-.

As depicted in the example of, the autonomous vehicleis traveling along a first route through the driving environmentand the autonomous vehicleis traveling along a second route through the driving environment. While the autonomous vehicleand the autonomous vehicleare in proximity of each other, the radar systemand the radar systemcan be identified as likely to experience cross-radar interference. The term “likely to experience cross-radar interference” is intended to refer to the radar systemand the radar systemlikely experiencing cross-radar interference if the techniques described herein were not employed.

Without employing the techniques described herein, a transmitter of the radar systemof the autonomous vehicleand a transmitter of the radar systemof the autonomous vehicle can both transmit radar signals into the driving environment, where such radar signals are time synchronized. Accordingly, a receiver of the radar systemof the autonomous vehiclecan receive a reflected radar signal responsive to the radar signal transmitted by the transmitter of the radar systemas well as an interfering radar signal from the radar systemof the autonomous vehicle. For instance, the radar signal transmitted by the transmitter of the radar systemcan propagate through the driving environment, reflect off an object, and return to the receiver of the radar systemas the reflected radar signal. Moreover, the interfering radar signal can be transmitted by the transmitter of the radar systemof the autonomous vehicleand propagate through the driving environmentto the receiver of the radar systemof the autonomous vehicle(e.g., the interfering radar signal can directly propagate through the driving environmentfrom the transmitter of the radar systemto the receiver of the radar system, propagate from the transmitter of the radar systemto the objectand reflect off the objectto the receiver of the radar system, etc.). Similarly, a receiver of the radar systemof the autonomous vehiclecan receive a reflected radar signal responsive to the radar signal transmitted by the transmitter of the radar systemas well as an interfering radar signal from the radar systemof the autonomous vehicle.

In contrast to the foregoing scenario, the radar systemand the radar systemcan be controlled to mitigate such cross-radar interference which may otherwise occur between the radar systems-due to the relative locations of the autonomous vehicles-. More particularly, one of the radar systems-can be selected to operate in an active mode and the other one of the radar systems-can be selected to operate in a passive mode during a time period responsive to identifying that the radar systemand the radar systemare likely to experience cross-radar interference during the time period. When operating in the active mode, both a transmitter and a receiver of a radar system are enabled. Moreover, when operating in the passive mode, a transmitter of a radar system is disabled while a receiver of the radar system is enabled.

According to an example, the autonomous vehicleand the autonomous vehiclecan be within radar range of each other during a time period as the autonomous vehicletravels along a first route through the driving environmentand the autonomous vehicletravels along a second route through the driving environment. Following this example, it can be determined that the radar systemof the autonomous vehicleand the radar systemof the autonomous vehiclewould likely experience cross-radar interference during a time period given the synchronization between the radar systemand the radar system. To mitigate the cross-radar interference, one of the radar systems-can operate in the active mode and the other one of the radar systems-can operate in the passive mode during the time period. Pursuant to an illustration, the radar systemcan be caused to operate in the active mode and the radar systemcan be caused to operate in the passive mode during the time period. The foregoing selection specifying which radar system-is in the active mode and which radar system-is in the passive mode is described in greater detail below. Further, the radar system operating in the passive mode (e.g., the radar systemin the foregoing illustration) can be updated with transmission information pertaining to the radar system operating in the active mode (e.g., the radar systemin the foregoing illustration). The transmission information pertaining to the radar system operating in the active mode, which can be provided to the radar system operating in the passive mode, can include location information specifying the location of the radar system operating in the active mode, waveform information specifying a waveform of a radar signal transmitted by the radar system operating in the active mode, and/or timing information specifying timing of the radar signal transmitted by the radar system operating in the active mode. The location information can include information pertaining to the current location and/or future location(s) of the radar system operating in the active mode. Moreover, various types of waveforms are intended to fall within the scope of the hereto appended claims (e.g., frequency modulated continuous wave (FMCW), orthogonal frequency division multiplexing (OFDM), etc.).

Again following the above illustration where the radar systemoperates in the active mode and the radar systemoperates in the passive mode, the transmitter of the radar systemcan transmit a radar signal into the driving environment. The receiver of the radar systemcan receive a reflected radar signal responsive to the transmitted radar signal (e.g., the radar signal can be transmitted into the driving environmentfrom the radar system, reflect off the object, and return to the radar system); thus, the radar systemcan detect the objectbased upon such reflected radar signal. Moreover, the receiver of the radar systemof the autonomous vehiclecan receive a reflected radar signal from the driving environmentresponsive to the radar signal transmitted by the transmitter of the radar systemof the autonomous vehicle(e.g., the radar signal transmitted into the driving environmentfrom the radar systemcan further reflect off the objectand propagate to the radar system). Thus, the radar systemcan record radar data from the driving environmentwhile in the passive mode without transmitting a radar signal into the driving environment(e.g., the radar systemcan receive a reflected radar signal responsive to a radar signal transmitted into the driving environmentby a differing radar system). The radar systemoperating in the passive mode can detect the objectbased on the reflected radar signal which is received responsive to the radar signal transmitted by the radar systemoperating in the active mode. Accordingly, the reflected radar signal from an interfering source can be utilized as an offboard source of radar illumination by the radar systemoperating in the passive mode.

According to an illustration, the autonomous vehicleand the autonomous vehicleare operating within radar range of each other in the driving environment. Without employing the techniques set forth herein, the radar systemof the autonomous vehicleand the radar systemof the autonomous vehiclewould likely interfere with each other, given the timing synchronization between the radar systemsand. Instead, one of the radar systemsand(e.g., the radar systemin the continuing example) is in the active mode and the other one of the radar systemsand(e.g., the radar systemin the continuing example) is in the passive mode during a time period. Communications between the autonomous vehicles-and/or from a server computing system can enable coordination of the respective modes of the radar systemsand. Further, location information specifying the location of the radar systemin the active mode can be provided to the radar systemin the passive mode. In the passive mode, the radar systemrecords radar signals but does not transmit radar signals. The radar systemoperating in the passive mode can mix radar signals, perform fast Fourier transform (FFT) processing, detect a direct path pulse train of the radar signal from the radar systemoperating in the active mode, and/or detect reflections of the radar signal from the radar systemoperating in the active mode present in a field of view of the radar system. Moreover, the radar systemoperating in the passive mode can compute offsets from the direct path. Using the computed offsets, locations of both the radar systemand the radar system, passive direction of arrival beamforming, and geometric transforms, a location of a target (e.g., the object) in the field of view of the radar systemcan be computed (e.g., by the radar systemoperating in the passive mode and/or a computing system of the autonomous vehicleincluding the radar systemoperating in the passive mode). It is contemplated that the foregoing approach can be scaled to multiple autonomous vehicles, with radar systems of vehicles operated in passive or active mode so as to mitigate interference across the group of vehicles and/or enhance localization of targets in fields of view of the radar systems.

The techniques set forth herein can be employed to mitigate cross-radar interference between radar systems within a fleet of vehicles (e.g., the autonomous vehicles-) while also enhancing radar perception. For instance, multistatic radar can enhance the ability of a radar system to detect a target object by illuminating the target object from multiple angles. Accordingly, tracking capabilities can be enhanced by leveraging the opportunistic multistatic radar approaches described herein. The foregoing can be supported by leveraging cooperation between the autonomous vehicles-in the fleet as well as localization techniques for determining locations of the autonomous vehicles-in the driving environment. Thus, randomness of the locations of the autonomous vehicles-over time as the vehicles travel along respective routes in the driving environmentcan be opportunistically employed using the techniques described herein (e.g., the autonomous vehicles-need not purposefully be maneuvered into given positions in the driving environmentto mitigate the cross-radar interference, rather decisions regarding modes in which the radar systems are to operate can be made based on the locations as the vehicles follow their respective routes).

Now turning to, illustrated is an exemplary systemin which a server computing systemopportunistically manages passive multistatic radar processing within a fleet of autonomous vehicles-. As depicted, the systemincludes the autonomous vehicleand the autonomous vehicle; yet, it is contemplated that the systemcan include substantially any number of autonomous vehicles, each of which can be substantially similar to the autonomous vehicles-. According to an example, the server computing systemcan be a remote server computing system separate from the autonomous vehicles-in the fleet. Pursuant to another example, the server computing systemcan be an on-vehicle server computing system (e.g., one or more autonomous vehicles in the fleet of autonomous vehicles-can include the server computing system). The server computing systemincludes a processorand memory; the memoryincludes computer-executable instructions that are executed by the processor. Pursuant to various examples, the processorcan be or include a graphics processing unit (GPU), a plurality of GPUs, a central processing unit (CPU), a plurality of CPUs, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a microcontroller, a programmable logic controller (PLC), a field programmable gate array (FPGA), or the like. Moreover, the server computing systemcan include a data store.

The memoryof the server computing systemcan include an interference analysis componentand a mode selection component. The interference analysis componentcan identify that a first radar system of a first autonomous vehicle and a second radar system of a second autonomous vehicle are likely to experience cross-radar interference during a time period as the first autonomous vehicle travels along a first route through a driving environment and the second autonomous vehicle travels along a second route through the driving environment. For instance, the interference analysis componentcan identify that the radar systemof the autonomous vehicleand the radar systemof the autonomous vehicleare likely to experience cross-radar interference during the time period. It is to be appreciated that the interference analysis componentcan identify that more than two radar systems of differing autonomous vehicles are likely to experience cross-radar interference between each other during the time period. Thus, while many of the examples set forth below describe two radar systems (e.g., the radar systemsand) being identified as likely to experience cross-radar interference and subsequently controlled, these examples can be extended to scenarios where more than two radar systems are identified as likely to experience cross-radar interference and controlled to support opportunistic passive multistatic radar processing.

As noted above, the interference analysis componentcan identify that the radar systemof the autonomous vehicleand the radar systemof the autonomous vehicleare likely to experience cross-radar interference during the time period. The interference analysis componentcan identify that the radar systemof the autonomous vehicleand the radar systemof the autonomous vehicleare likely to experience cross-radar interference based on a distance between the radar systemand the radar system, a first field of view of the radar system, and a second field of view of the radar system. For instance, the interference analysis componentcan utilize location information pertaining to locations of the autonomous vehicleand the autonomous vehiclewithin the driving environment to determine that the radar systemand the radar systemare within radar range of each other. For example, radar range can be specified as the radar systemand the radar systembeing within 100 meters of each other, 250 meters of each other, or the like. Moreover, the interference analysis componentcan determine that the radar systemand the radar systemare oriented with respect to each other such that the cross-radar interference would likely occur based on the radar systembeing within the field of view of the radar systemand/or the radar systembeing within the field of view of the radar system. The interference analysis componentcan additionally or alternatively employ information specifying orientations of the autonomous vehicleand the autonomous vehiclewithin the driving environment as well as information indicating positions of the radar systems-relative to the autonomous vehicles-(e.g., orientation of the radar systemrelative to the autonomous vehicle, etc.) to identify that the radar systemof the autonomous vehicleand the radar systemof the autonomous vehicleare likely to experience cross-radar interference during the time period.

Pursuant to another example, the interference analysis componentcan additionally or alternatively identify actual instances of cross-radar interference between radar systems. Thus, the techniques described herein can be applied to such scenarios of actual cross-radar interference.

The mode selection componentcan select radar system(s) to operate in the active mode and radar system(s) to operate in the passive mode. Continuing the foregoing example, the mode selection componentcan select the radar systemof the autonomous vehicleto operate in the active mode and the radar systemof the autonomous vehicleto operate in the passive mode during the time period. The mode selection componentcan cause the server computing systemto transmit, to the autonomous vehicle, a control signal to cause the radar systemto operate in the passive mode during the time period. Moreover, the mode selection componentcan cause the server computing systemto transmit, to the autonomous vehicle, a control signal to cause the radar systemto operate in the active mode during the time period. However, according to another example, it is contemplated that a control signal need not be sent to cause a radar system to operate in the active mode (e.g., a radar system can default to operate in the active mode unless a control signal is received causing the radar system to operate in the passive mode).

The data storecan further include transmission information. The transmission informationcan include location information specifying locations of the radar systems-, waveform information specifying waveforms of radar signals transmitted by the radar systems-, timing information specifying timing of the radar signals transmitted by the radar systems-, and so forth. According to an example, the interference analysis componentcan identify that the radar systems-are likely to experience cross-radar interference during a time period based on at least some of the transmission informationretained in the data store.

Pursuant to a further example, the mode selection componentcan cause the server computing systemto transmit at least some of the transmission informationto one or more of the autonomous vehicles-. Reference is again made to the example above where the mode selection componentselects the radar systemof the autonomous vehicleto operate in the active mode and the radar systemof the autonomous vehicleto operate in the passive mode during the time period. Following this example, the mode selection componentcan further cause the server computing systemto transmit, to the autonomous vehicle, transmission informationpertaining to the radar systemof the autonomous vehicle. Thus, the transmission informationpertaining to the radar systemoperating in the active mode can be provided to the autonomous vehicleincluding the radar systemoperating in the passive mode during the time period. Such transmission informationcan be utilized by the radar systemoperating in the passive mode to detect object(s) from received radar signals. As noted above, the transmission informationpertaining to the radar systemoperating in the active mode, which can be provided to the radar systemoperating in the passive mode, can include location information specifying a location of the radar system, waveform information specifying a waveform of a radar signal transmitted by radar system, and/or timing information specifying timing of the radar signal transmitted by the radar system.

According to another example, it is contemplated that the mode selection componentcan control a power level of a radar system operating in active mode. Thus, a control signal sent to the radar system operating in the active mode can further specify the power level at which the radar system is to transmit a radar signal.

The autonomous vehicleis now described in greater detail. It is contemplated that the autonomous vehicle(as well as other autonomous vehicle(s)) can be substantially similar to the autonomous vehicle(e.g., the radar systemas well as other radar system(s) can be substantially similar to the radar system). The radar systemincludes a transmitterand a receiver. When the radar systemof the autonomous vehicleoperates in the active mode, the transmitterand the receiverof the radar systemare both enabled. Moreover, when the radar systemof the autonomous vehicleoperates in the passive mode, the receiverof the radar systemis enabled and the transmitterof the radar systemis disabled. When enabled, the transmittercan transmit a radar signal into an environment; the transmitterdoes not transmit a radar signal when disabled. Moreover, the receivercan receive a radar signal from the environment regardless of whether the transmitteris enabled. The radar systemof the autonomous vehicle(as well as other radar system(s) of other autonomous vehicle(s)) can also include a transmitter and a receiver, which can operate in a similar manner as compared to the radar system.

The autonomous vehiclefurther includes the computing systemin communication with the radar system. The computing systemincludes a processorand memory; the memoryincludes computer-executable instructions that are executed by the processor. Pursuant to various examples, the processorcan be or include a graphics processing unit (GPU), a plurality of GPUs, a central processing unit (CPU), a plurality of CPUs, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a microcontroller, a programmable logic controller (PLC), a field programmable gate array (FPGA), or the like. The memoryincludes the radar control system, which controls operation of the radar system. While the computing systemcan be separate from, but in communication with the radar system, in other embodiments it is contemplated that the radar systemcan include the computing system(e.g., the radar systemcan include the radar control system).

The radar control systemcan include a transmitter control componentand a signal processing component. The transmitter control componentis configured to control the radar systemto operate in one of the active mode or the passive mode during a given time period. For example, the transmitter control componentcan control the radar systemto operate in the active mode during the given time period; thus, the transmitter control componentcan enable both the transmitterand the receiverof the radar systemduring the given time period. According to another example, the transmitter control componentcan control the radar systemto operate in the passive mode during the given time period; accordingly, the transmitter control componentcan enable the receiverand disable the transmitterduring the given time period.

The receivercan receive a radar signal from the driving environment. The received radar signal can be responsive to a radar signal transmitted by the transmitterof the radar system(if enabled by the transmitter control component) and/or responsive to a radar signal transmitted by transmitter(s) of differing radar system(s) (e.g., the radar system). The signal processing componentcan detect an object in the driving environment based on the radar signal received by the receiverof the radar system.

According to an illustration, when the transmitter control componentcauses the radar systemto operate in the active mode, the transmittertransmits a radar signal into the driving environment. The radar signal propagates from the transmitterand can reflect off an object such that a reflected radar signal can be received by the receiver. The signal processing componentcan detect the object based on the reflected radar signal.

Pursuant to another illustration, when the transmitter control componentcauses the radar systemto operate in the passive mode, the transmitteris inhibited from transmitting. Rather, a reflected radar signal responsive to a radar signal transmitted by the radar systemof the autonomous vehiclecan be received by the receiverof the radar system. For instance, the radar signal transmitted by the radar systemcan be reflected by an object in the driving environment, and the reflected radar signal can propagate to the receiverof the radar system. The signal processing componentcan detect the object in the driving environment based on the reflected radar signal and the transmission information pertaining to the radar systemof the autonomous vehicle. The signal processing componentcan utilize timing information and waveform information pertaining to the radar signal transmitted by the radar systemof the autonomous vehicleas well as location information of the radar systemand location information of the radar systemto detect the object based on the reflected radar signal received by the receiver. By having the waveform information used by the radar systemof the autonomous vehicle, the signal processing componentcan have a priori knowledge that can be utilized to detect the object from the reflected radar signal. For example, the signal processing componentcan output data specifying a location of the object, velocity of the object, direction of movement of the object, and so forth.

Moreover, it is to be appreciated that the mode in which the radar systems-operate can change over time. Again reference is made to the example above where the mode selection componentselects the radar systemof the autonomous vehicleto operate in the active mode and the radar systemof the autonomous vehicleto operate in the passive mode during the time period. During a differing time period, the mode selection componentcan select the radar systemof the autonomous vehicleto operate in the passive mode as the autonomous vehicletravels along the route through the driving environment. Thus, the mode selection componentcan cause the radar systemof the autonomous vehicleto switch from the active mode to the passive mode. The mode selection componentcan further cause the server computing systemto transmit, to the autonomous vehicle, a control signal to cause the radar systemto operate in the passive mode during the differing time period. The mode selection componentcan also cause the server computing systemto transmit, to the autonomous vehicle, transmission informationpertaining to the radar systemof the autonomous vehicle. The transmitter control componentcan control the radar systemto operate in the passive mode as described herein responsive to receipt of such control signal.

Additionally or alternatively, during the differing time period, the mode selection componentcan select the radar systemof the autonomous vehicleto operate in the active mode as the autonomous vehicletravels along the route through the driving environment (e.g., the radar systemcan be switched from the passive mode to the active mode). The mode selection componentcan further cause the server computing systemto transmit, to the autonomous vehicle, a control signal to cause the radar systemto operate in the active mode during the differing time period.

Further, it is contemplated that the radar systemof the autonomous vehicleand the radar systemof the autonomous vehiclecan both operate in the active mode when cross-radar interference is not likely to be experienced by either of the radar systemsand.

With reference to, illustrated is an exemplary systemin which opportunistic passive multistatic radar processing within a fleet of autonomous vehicles-is managed by the autonomous vehicles-. The systemincludes the autonomous vehicleand the autonomous vehicle; however, it is again contemplated that the systemcan include more than two autonomous vehicles-. Moreover, while the autonomous vehicleis described in detail, it is contemplated that other autonomous vehicle(s) in the system(e.g., the autonomous vehicle) can be substantially similar to the autonomous vehicle.

As described above, the autonomous vehicleincludes the radar system (including the transmitterand the receiver) and the computing system(including the processorand memory). The memoryincludes the radar control system. In the example of, the radar control systemincludes an interference analysis component(e.g., the interference analysis component) and a mode selection component(e.g., the mode selection component). Moreover, the radar control systemofagain includes the transmitter control componentand the signal processing component. Accordingly, the autonomous vehicleand the autonomous vehiclecan control whether the respective radar systemsandare to operate in the active mode or the passive mode (rather than being controlled by a server computing system) in the example of. Thus, vehicle-to-vehicle communications can be exchanged between the autonomous vehicleand the autonomous vehicle(as well as other autonomous vehicle(s) that are nearby) to enable such control of the respective radar systemsand. The transmitter control componentand the signal processing componentcan operate in a similar manner as described above responsive to a mode of the radar systembeing selected by the mode selection component.

The interference analysis componentis configured to identify whether the radar systemof the autonomous vehicleand a differing radar system of a differing autonomous vehicle are likely to experience cross-radar interference during a given time period as the autonomous vehicleand the differing autonomous vehicle travel along respective routes. Similar to the interference analysis componentof the server computing systemof, the interference analysis componentcan identify that the radar systemof the autonomous vehicleand the differing radar system of the differing autonomous vehicle are likely to experience cross-radar interference during the given time period based on a distance between the radar systems (e.g., a distance between the radar systemand the radar system), a field of view of the radar system(e.g., whether the radar systemis within the field of view of the radar systemduring the given time period), etc. Accordingly, the interference analysis componentcan receive location information pertaining to differing radar system(s) of differing autonomous vehicle(s), orientation information of such differing radar system(s), and the like (e.g., such information can be received from the differing autonomous vehicles, from a server computing system such as the server computing system, etc.). Pursuant to an illustration, the interference analysis componentcan identify that the radar systemand the radar systemof the autonomous vehicleare likely to experience cross-radar interference during the given time period.

Moreover, the mode selection componentis configured to select a mode (e.g., active mode or passive mode) of the radar systemfor the given time period responsive to the interference analysis componentidentifying that cross-radar interference is likely to be experienced. The mode selection componentcan also select mode(s) of the other radar system(s) with which the radar systemis likely to experience cross-radar interference during the given time period. For instance, the mode selection componentcan exchange messages with mode selection component(s) of the other radar system(s) of the other autonomous vehicle(s) (e.g., a mode selection component of the autonomous vehicle) to coordinate the modes selected for the radar systemand the other radar system(s) that are likely to experience cross-radar interference during the time period. Thus, following the illustration above where the interference analysis componentidentifies that the radar systemand the radar systemof the autonomous vehicleare likely to experience cross-radar interference during the given time period, the mode selection componentcan select the radar systemto operate in one of active mode or passive mode and can select the radar systemto operate in the other one of active mode or passive mode during the given time period. Further, it is contemplated that the mode selection componentcan cause the mode of the radar systemto change during differing time periods.

According to an example, when the mode selection componentcauses the radar systemto operate in the active mode and the radar systemis to operate in the passive mode, the mode selection componentcan cause the autonomous vehicleto send transmission information to the autonomous vehicle. The transmission information sent from the autonomous vehicle pertains to the radar systemand can be utilized by a signal processing component of the autonomous vehicleto detect object(s) based on radar signal(s) received by the radar systemwhile the radar systemis operating in the passive mode. Similar to above, the transmission information can include location information specifying a location of the radar system, waveform information specifying a waveform of a radar signal transmitted by the transmitter, timing information specifying timing of the radar signal transmitted by the transmitter, and so forth.